Mumbai: The Central Bureau of Investigation (CBI) on Tuesday arrested five functionaries of the companies of diamond trader Nirav Modi and his uncle Mehul Choksi who are allegedly behind the Rs 11, 400 crore Punjab National Bank (PNB) scam.

The CBI also arrested Kapil Khandelwal, chief financial officer, Nakshatra and Gitanjali groups and Niten Shahi, manager, Gitanjali group-both belonging to the group led by Choksi.

Meanwhile, the Income Tax Department on Tuesday raided 20 premises linked to Gitanjali Gems and suspected shell firms in connection with an alleged tax evasion case against them, PTI quoted official sources as saying.

They said the searches, launched at about 4 pm, were being conducted in Mumbai, Pune, Surat, Hyderabad, Bengaluru and a few other cities against 13 companies linked to Choksi, his jewellery firm Gitanjali Gems and others.

Choksi, Nirav Modi and others are being investigated by multiple probe agencies after it recently came to light, following a complaint by the Punjab National Bank, that they had allegedly cheated the lender of Rs 11,400 crore, with the purported involvement of a few employees of the bank.

Banks were confidentially warned thrice against misuse of SWIFT: RBI

On the other hand, the Reserve Bank of India (RBI) said on Tuesday that it had "confidentially" cautioned banks thrice since August 2016 on the risks arising from the malicious use of SWIFT system, and has decided to set up a panel to look into the rising incidence of frauds.

In a statement, the RBI said that as part of the ongoing efforts for strengthening of the supervisory framework in the country, it has been issuing necessary instructions to banks from time to time on a variety of issues of prudential supervisory concern, including the management of operational risks inherent in the functioning of banks.

RBI further said it "had, therefore, confidentially cautioned and alerted banks of such possible misuse, at least on three occasions since August 2016, advising them to implement the safeguards detailed in the RBI’s communications, for pre-empting such occurrences".

Banks have, however, been at varying levels in implementation of such measures, it added.

"In the wake of SWIFT-related fraud involving significant amount, reported recently by PNB, RBI has today reiterated its confidential instructions and mandated the banks to implement, within the stipulated deadlines, the prescribed measures for strengthening the SWIFT operating environment in banks," the statement said.

The central bank said it has decided to constitute an Expert Committee under the chairmanship of Y H Malegam, a former member of the Central Board of Directors of RBI.

The committee, RBI said, has been set up in view of large divergences observed in asset classification and provisioning in the credit portfolio of banks as well as the rising incidence of frauds in the banking system.

The panel will look into the reasons for high divergence observed in asset classification and provisioning by banks vis-a-vis the RBI’s supervisory assessment, and the steps needed to prevent it.